Safety device for boilers



Oct. 14. 1924.

SAFETY DEVI CE FOR BOILERS Filed March 28 1923 iflfijjl" rlififlliii s ia I 1 l l l I I 7 i 29 a v q a 1a 2 WITNESSES r INVENTOR I 4F 59 5,9 7 22 a, BY W4 G A TTORNE YS Patented Oct. 14, 1924.

UNITED STATES JOHN J. MUHIJEBACH, on NEW YORK, n. Y.

SAFETY DEVICE FOR BOILERS.

Application filed March 28, 1923.

To all whom it may concern:

Be it known that I, JOHN J. MUHLEBACH, a citizen of the United States,and a resident of the city of New York, Far Rockaway, borough of Queens,in the county of Queens and State of New York, have invented a new andImproved Safety Device for Boilers, of which the following is a full,

clear, and exact description.

This invention relates to improvements in boilers, and has particularreference to a safety device therefor.

The present invention is especially designed as an improvement on theconstruc tion illustrated and described in my previous application,Serial Number 617 ,132, filed February 5th, 1923. In said applicationthe safety device is so constructed and mounted that it is necessary toopen the valve which controls the flow of water to the compartment ofthe boiler before any indication will be given as to the condition ofthe water within said compartment.

An object of the present invention is to provide a safety device whichwill operate, when the level of the water in the water compartment fallsbelow a predetermined point, to indicate such low level irrespective ofthe condition of the valve which controls the supply of water to saidcompartment.

Another object is the provision of a device which, when operated by thefalling of the level of water in the water compartment below apredetermined point, will divert the water supply for said compartmentto the floor surrounding the boiler without passing through the walls ofthe latter.

The above and other objects will appear more clearly from the followingdetail description,when taken in connection with the accompanyingdrawing, which illustrates preferred embodiments of the inventive idea.

In the drawing- Figure 1 is a fragmentary side elevation of a boiler,partly broken away and shown in section, illustrating one form of thepresent invention;

Figure 2 is an enlarged longitudinal section through the safety deviceshown in Figurel; and

Figure 3' is a view similar to Figure 2, showing adifferent formfof theinvention.

Referring to: the drawing, the numeral 4 indicatesa boiler of any wellknown con- 'struction including the outer wall 5 and. the

Serial No. 628,379.

inner fire box wall 6 spaced from said wall to form the watercompartment 7. The boiler further includes the usual grate 8 and dooropening 9 closed byth'e door 10.

It is proposed in the present invention, as in my previous applicationabove referred to, to arrange the safety device so that when the same isoperated upon the level of the water falling below a predetermined pointin the water compartment 7, the supply for said compartment willautomatically be shut off and diverted through the body to pointsexterior of the boilerto indicate such low level in the watercompartment. As previously indicated above, this latter result couldonlybe accomplished, in my previous application, by opening the valvewhich controlled the inlet pipe from which the supply of water is fedinto the water compartment. In the present invention, this result'may beaccomplished whether said valve be opened or closed, thus rendering thedevice more efficient in its operation.

In the form of the invention shown in Figures 1 and 2, the water isdiverted from the water compartment and projected through the body ofthe device, when said device is operated, in the same manner asdescribed in connection with my previous application, that is, the waterwill flow through the device and over the grate and toward the dooropening 9. Thus part of the water will fall onto the fire, at least partially reducing the temperature thereof, and some of the water willeither pass through the door opening 9 and onto the floor surroundingthe boiler, or impinge against the door 10, if said door is in closedposition. In the latter instance, some of the water will flow over thefront of the boiler adjacent the door opening and the remainder willfall back onto the grate S. I

The safety device, as illustrated in Figures 1 and 2, comprises a body11 having its inner.

screw threaded end mounted in an opening 12 formed in the wall 6 at therear of the boiler and its intermediate screw threaded portion engagedin a similar opening 13 in the outer wall 5. The portion of the body 11thus disposed within the water compartment 7 is provided with oppositelydisposed openings 14 through which water will flow from the body 11 intothe water compartment when it is desired to replenish the supplytherein. The

inner end of the body 11 is normally closed 3i 3e 19 slidabl 1 mountedin a bearin 52-0 and having its inner end engaged with the plug 15. Theouter end of the body 11 has mount ed therein a bushing 21 provided with21 ionflitudinal ooenin 22 in which is slidabl c i mounted a valve 23which normally closes the inlet end of a by-pass 24 formed in saidbushing. The valve 23 has a stem the inner end of which is provided withan enlargement 26 to which the outer end oi the feed pipe 19 isconnected in any suitable manner. A; coil spring is interposed betweenthe inner end of the bushing 21 and the enlargement 26 and exerts arearward pres sure upon said enlargement to constantly maintain theinner end of the pipe 19 in engagement with the plug 15.

The outer end of the body 11 is also provided with a lateral extension28 having a screw threaded opening for receiving one endot an inlet pipe29 having a valve 30 for controlling the iiow oi water from said pipeinto said body and triom thence into the water compartment when thesafety device is in its normal condition.

The valve 30 is interposed between. the body 11 and one end of by passpioe connected to the inlet pipe 2%), the other end of said lay-passpipe being; connected to a nipple 32 mounted in the bushing 21. By thusarranging the bypass pipe 81 a portion of the water from the inlet pipewill be diverted around the valve 30 and through said by pass pipe to exa continuous pres sure upon the valve 23 which normally prevents theflow of water through the by-pass 24.

Should the level oi the water in the water coinpartmenttall below thebody 11 and thus expose the plug L3 to the action oi. heat from the fireon grate 8, it will be obvious that the fusible material 16 will berapidly fused b said heat whereupon the plug will be d lodged by thecombined pre -ure oi spring 27 and the water impingin the forward end ofthe valve '23; sure willcausethe :teed pipe 19 and valve to bemovedinwardly until the valve 18 engages the valve seat 17 to closecommunication'between the inlet pipe 29 and the water compartment. Whenthe valve has moved.

.suthciently to uncover the adjacent end of the bypass 24 the waterflowing through the ,pipeBIWil'lenter the body ll throug'zfh said"by-pass; 24' and .will then pass through openla s-esteemed in theptorwardend orfithe formed in the body 37,

c 1 1 ble plug feed pipe 19. The water thus entering said teed pipeunder constant pressure, irrespeo tive of the condition of the valve 30,will be projected through said pipe, over the grate 8 and toward thedoor opening 9, as previously described. 7

In the form of the invention shown in Figure 3., it is proposed toutilize the steam generated in the water compartment to cause theoperation of: the safety device when the level of the water in saidcompartment talls below that of said device. Also contrary to theconstruction shown in Figure 2, it-is further proposed to divert thewater from the water compartment when the device is operated and projectit through the body and directly onto the floor surrounding the boilerinstead of over the grate and toward the door opening. Theretoie insteadof extend i the body of the device through the outer and inner walls and6, a fusible plug including the shell 3st and central portion 35 otfusible material is mounted in a screw threaded i pening 36 formed inthe wall 5. pi e bony 37 01 the device then has its in ner end'suitablymounted in the shell 34 and communication between the body and thecompartment 7 is established through an elbow 38 one end of which isconnected to the body and the other end threaded in an opening' 39 inthe wall At a point contig uous the (,(ElillGCiLlOl'l of the elbow 38with the body the hater is provided with avalve seat il) designed to beclosed by a normally inoperative valve i1 carried by the valve stem e2,the inner end of which engages the fusible pine, while the outer end isslidably'mounted in the bushii 5 13 supported by the outer end of thebody 37. The bushing 48 is provided with a pas, re l lwhich communicateswith a port or b -pass t in said bushing. said port in turn registeringwith an opening; 46

A valve 47 is slidably mounted in the bushing 43 and normally clo es theport so that water in the bypass pipe 41-8 similar to the pipe 31.willbe prevented from flowing: through said port 45. The bypass pipe isconnected to the valve-controlled inlet pipe 49 in the same manner asillustrated in l igure 1 i From the toregz i description, it will beobvious that when the water in the co n partment 7 falls below the levelof the fusithe portioirof the wall Isurroundin the plug will becomeoverheated to such .an extent as to fuse the material whereupon thepressure of water in the by-pass pipe as against the valve eTwill causethe latter valve to move inwardly imparting a similar movement tothe'valve 41, which then engages the seat e0 to'close communicationbetween thei inlet pipe 49 and the elbow88 through the bodyBZThe inwardmovement of the valve 47 uncovers the port or bypass i and 1 thuspermits. the

water to flow from the bypass pipe 48 through said port and the opening46 onto the floor surrounding the boiler. It will be apparent that thisaction takes place whether the valve controlling the inlet pipe 49 isopened or closed.

Whatis claimed is:

1. In a safety device for boilers, a body normally having communicationwith the water compartment of a boiler, a valve-controlled inlet pipefor feeding water through said body into said compartment, a normallyclosed by-pass pipe connecting said inlet pipe with said body, and meansin said body operable upon the level of water in said compartmentfalling below a predetermined point for closing communication betweensaid inlet pipe and compartment and for opening said by-passto permitwater to flow through said body without entering said compartment.

2. In a safety device for boilers, a body normally having communicationwith the water compartment of a boiler, two inlet pipes communicatingwith said body, a valve in one of said pipes for controlling the flow ofwater through said body into said compartment, means in said body fornormally closing the other inlet pipe, and means in said body operablewhen the water in said compartment falls below a predetermined level forclosing communication between the first named ipe and said compartmentand for causing the last named means to open the second named inlet pipeto permit water to flow therefrom through said body irrespective of thecon dition of said valve.

3. In a safety device for boilers, a body having communication with thewater compartment of a boiler, an inlet pipe from which water is fedthrough saidbody into said compartment, a member movable longitudinallyof said body, a valve carried by said member for controlling the flow ofwater into said compartment, fusible means carried by said body fornormally retaining said member and valve in inoperative position, meansfor moving said member and valve to operative position to stop the flowof water into said compartment when said fusible means is fused, and abypass connecting said inlet pipe and body for permitting the water topass through said body when said valve is in its operative position.

4. In a safety device for boilers, a body having communication with thewater compartment of a boiler, an inlet pipe from which water is fedthrough said body itno said compartment, a valve for controlling thepassage of water through said inlet pipe, a member movablelongitudinally of said body, a valve carried by-said member forcontrolling the flow of water into said compartment, fusible meanscarried by said body for normally retaining said member and the secondnamed valve in inoperative position, means for moving said member andvalve to operative position to stop the fiow of water into saidcompartment when said fusible means is fused, and a by-pass for saidinlet pipe for permitting the passage of water through said bodywhen'said second named valve is operated irrespective of the conditionof the valve controlling said inlet pipe.

5. In a safety device for boilers, a body having communication with thewater compartment of a boiler, an inlet pipe for feeding water throughsaid body into said compartment, a by-pass pipe connecting said inletpipe with said body, means for con trolling the flow of water throughsaid inlet pipe and through said body into said compartment and forpreventing the flow of water from said by-pass pipe'into said body, andmeans in said body operable when the level of Water in said watercompartment falls below a predetermined point for permitting thepressure of water in said bypass pipe to operate the last named means toshut off communication between said inlet pipe and compartment andestablish communication between said by-pass pipeand body.

6. In a safety device for boilers, a body having communication with thewater compartment of a boiler, an inlet pipe for feeding water throughsaid body into said compartment, a normally inoperative valve in saidbody for controlling said feed, a member carried by said body and havinga normally closed by-pass through which water maybe projected throughsaid body, a by-pass pipe for establishing communication between saidinlet pipe and said by-pass, a second valve operable with the firstnamed valve and normally closing the communication between said by-passpipe and bypass, and means operable when the water in said compartmentfalls below a predetermined level for permitting the first named valveto move to operative position and the second named valve to inoperativeposition.

JOHN J. MUHLEBACH.

